The invention relates generally to gas turbines and, more specifically, to variable stator vane assemblies used with gas turbines.
In a gas turbine, air is pressurized in a compressor and channeled to a combustor where it is mixed with fuel and ignited for generating hot combustion gases. The hot combustion gases flow downstream into one or more turbine stages, which extract energy therefrom for producing useful work. At least some known compressors have a plurality of axial stages that compress the air in turn as it flows downstream. Each compressor stage may include a row of rotor blades extending radially outwardly from a compressor spool or disk, and a cooperating row of stator vanes extending radially inwardly from an annular casing.
It would be desirable to enable independent hydraulic actuation of compressor inlet guide vanes (IGVs) and variable stator vanes (VSVs) for improved gas turbine efficiency, performance and load turndown capability. Vane angle settings between the two separate sets of vanes may be independently adjustable to allow the gas turbine compressor to operate more effectively. It would further be desirable to include trip functionality to provide compressor protection during emergency shutdown situations.